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Our current understanding of the long-term climate cycles shows that for the past 800,000 years, periods of approximately 100,000 years' duration, called Ice Ages, have been interrupted by periods of approximately 10,000 years, known as Interglacials. (We are now about 10,500 years into the present Interglacial.)

In the science fiction novel Fallen Angels (and in the appendix), Larry Niven and co-authors suggest that the only reason why we haven't fallen into a full-blown ice age yet is human-influenced global warming.

As for terminal moraines, the terminal moraine from the last ice age didn't so much run down the middle of Long Island as Long Island is a terminal moraine, as are the Watchung Mountains in New Jersey. (The moraine is the pile of stuff that accumulates at the leading edge of a glacier.)

The Watchung Mountains in New Jersey are Jurassic volcanic basalt left from when Africa rifted away from North America during the Pangea breakup; they are not moraines.

In many cases the Terminal Moraine of the glaciers is right next to the Watchungs, but the Watchungs themselves are volcanic basalts, so I'm really picking nits I guess.

Larry Niven and co-authors suggest that the only reason why we haven't fallen into a full-blown ice age yet is human-influenced global warming.

Isaac Asimov also suggested this idea in one of his non-fiction works (published earlier than Niven's work - could be an inspiration for his story). I've seen mention of it elsewhere as well. It's not an unusual idea and is plausible.